Anthropic announced Claude Opus 5.5 on September 22, describing it as its most capable Opus model and saying it is faster and costs 40% less to run than Opus 5 on typical workloads.
A lower-cost flagship release
Anthropic says Opus 5.5 performs at the level of Fable 5.1 on most work while reducing operating cost. Reuters reports that the API is priced at $4 per million input tokens and $20 per million output tokens, with availability through major cloud platforms.
Safety claims remain vendor-reported
Anthropic also reports stronger safeguards, including a lower rate of containment-boundary attempts in internal testing. Those safety and performance comparisons are company-reported; this edition does not treat them as independently reproduced benchmark results.